


Coming of Age

by astrosaur



Category: Sexy Zone
Genre: Age Swap, M/M, happy 18th Mari!, here have a fic that is mostly an excuse for group shenanigans, welcome to (German) adulthood
Language: English
Status: Completed
Published: 2018-03-30
Updated: 2018-03-30
Packaged: 2019-04-14 19:12:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,030
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14142696
Author URL: https://archiveofourown.org/users/astrosaur/pseuds/astrosaur
Summary: Marius is a pro at being the youngest, so he's understandably out of his element when Sexy Zone's birth orders mysteriously switch up one day.





	Coming of Age

            In retrospect, Marius should have listened to his mom when she told him not to talk to her friends about his problems. At the end of the day, all it did was land him in a preposterous situation.

            That was his working theory, anyway. Maybe it wasn’t very sporting of him to blame the Takarazuka alumni without concrete evidence (aside from their otherworldly presence), but how else could he explain why, out of the blue, he suddenly had to deal with a 13-year-old Fuma squabbling with a 15-year-old Sou?

            That morning, Marius had been understandably gobsmacked to discover that he was the only one in his group whose age didn’t jump drastically from yesterday’s. The rest of Sexy Zone somehow regressed in age overnight, maintaining their age gaps with Marius, but on the opposite end. That meant Marius had a 15-year-old Sou, a 14-year-old Shori, a 13-year-old Fuma, and a 12-year-old Kento in his hands.

            Needless to say, this wasn’t what he had in mind when he’d expressed a long-standing desire not to be seen as a child anymore in front of his mom and her friends.

            He couldn’t recall what sparked that particular rant. It was likely another episode of Fuma ruffling his hair or some other gesture impugning his very-nearly-there adulthood. Fuma had a tendency to break those out whenever their interactions moved that much farther from younger brother tormenting to out-and-out flirting. Apparently it didn’t matter that he had already outgrown Fuma – physically, at least. When it came to their changing dynamics, it was an endless cycle of one step forward, two steps back.

            Nevertheless, Marius’s hope persisted that his fortune may one day be reversed. He found encouragement in the fact that Fuma was noticeably different with him. Fuma was different with all the members, of course. But he never exerted as much effort teasing Kento, never coddled Shori nearly as often (when he thought nobody noticed), never grappled with Sou in ways that made onlookers uncomfortable with implication. No amount of demonstrative baby-brothering erased that.

            At any rate, Marius would have to deal with that problem later on. After all, a slightly more pressing concern was that Fuma and others somehow slipped back into their pre-teen years.

            A tiny part of Marius wanted to do the exact same thing Fuma did to him – take childish revenge on this little boy with fluffy hair, lolicon voice, and voluminous cheeks, bickering with Sou over the semantics in a board game. Shori, invariably stuck in the middle, was on his phone pretending not to hear any of them. (That part wasn’t all that different.) Kento, stripped of the authority that came with being the eldest, ran off to fetch an adult to weigh in on their dispute.

            Marius had to put aside his bewilderment to handle the situation. First things first, he had to diffuse the ongoing incident. Taking a page from his memories, he took Fuma by his shoulders and firmly steered him away. He probably should have tried his luck with Sou first, but Sou was still the one person in the world he saw himself getting into an earnest fight with. He couldn’t see that changing whether Sou was three years older or three years younger than him.

            “Hey, Fuma-kun.” He swallowed down the knot that formed in his throat when he had to kneel down to be eye-level with this miniscule version of his bandmate. “Regardless of who’s wrong or right, is it worth this inconvenience?” Those words often worked to calm him down, whether it came from his parents, or his teachers, or Kento or Fuma, but he felt like a fraud reiterating them. He geared himself up to be verbally torn apart by this boy with a misleadingly angelic face.

            “Matsushima-kun is wrong,” Fuma answered simply.

            “Look, Marius-kun had to separate them!” another voice called out.

            Marius turned to see Kento pointing at him and Fuma as he tugged on a frazzled staff member’s shirt.

            “Well, then, Marius has it under control,” she said. She made eye contact with Marius, who then wondered if he was imagining a message of “this is your problem” telegraphed in her gaze.

            Marius didn’t know whether he wanted to laugh or cry that Kento, their nurturing and self-reliant leader, felt the need to tattle on them. _That_ Kento also wouldn’t have retreated to the dressing room, openly sulking about the outcome not going as planned.

            Fuma prodded Marius’s cheek with his finger and a long, sharp nail. “You’re making a weird face.”

            “Don’t be rude, Fuma-kun!” Marius grabbed his hand and inspected them. “And go cut your fingernails!” He was dismayed to find that it hadn’t been a full 24 hours as the eldest in Sexy Zone, and he had already turned into his mother.

 

●●●

 

            The next day, Marius still didn’t wake up in the normal world like he hoped he would. Instead, he had to walk into rehearsals, towering over each of his junior-sized bandmates, like they were about to do a sparkly retelling of Godzilla.

            They had dance lessons for a video they were back-dancing for in the same day. For the most part, Marius focused on helping Shori wind an overly long pastel scarf over and around his shoulders, only just managing not to choke him with it whenever Shori would let out a barely audible squeak to inform Marius of his pending strangulation. Fuma stepping in to help was all kinds of adorable, but he only made things worse, looping the scarf into every opening he could find and at one point somehow binding them together in a bundle of uselessness.

            While Marius tried to keep an eye on them so they didn’t end up accidentally creating a dual noose to slip into, he also had to politely turn every time Sou or Kento asked for approval on the dance steps they were learning.

            Shori looked at Marius with hopeful but guilty eyes after Sou completed a move that he was literally bending over backwards to do. “Marius-kun… I’m not sure about that step.”

            Shori drowning in his ill-fitting costume and calling him ‘Marius-kun’ had him positively melting. It was a nice change of pace to have that sweet face match the words coming out of its mouth, for once. “Don’t worry, Shori-kun. We’ll work on it together.”

            Just as a smile began to lighten the shadows on Shori’s face, a shrill yelp shook the room as Kento fell to the floor, in the middle of trying to emulate Sou. Kento landed hard on his behind before his head made a sick thudding sound, bouncing upon impact.

            “Kento-kun!” Marius shrieked in alarm. He bounded over to Kento, kneeling over him and checking his scalp for bumps. “Oh my god, are you okay?! Geez, be careful! You’re only twelve, you shouldn’t even be in Johnny’s yet!”

            “I’m sorry. I’ll do better.” Kento’s bottom lip did some foreign little wobble, and then he dashed to the door, recovering with a child’s resilience.

            Sou shook his head and whispered under his breath, “I know our manager said you’re too soft on him, but isn’t that going too far?”

            “Eh?” Marius replayed his words back in his head and realized how he might have come off. “EHHH?! I didn’t mean it like that!”

            The minute he took a step towards the direction of the exit, Shori’s large, pleading eyes gave him pause. “Do you have to go already?”

            “Er…” There was only one correct answer to that, going by the look on Shori’s face. Geez, were they this needy when they were younger? Marius turned to Sou, looking to share the burden with him. “Sou-chan, can you go and bring Kento-kun back?”

            Sou winced, already looking apologetic. “I can’t master the dance in time if I take off now. Fuma can chase after him, can’t you, Fuma? You’ve already memorized the steps, you don’t need more time with the instructors.”

            “Fuma-kun, could you please—”

            “Forget it,” Fuma replied without letting Marius finish. He switched a mutinous glare between Marius and Sou. “You’re going to lump me with the baby again and leave me with him, aren’t you? It’s not fair. We’re not that much younger than you.”

            Marius remembered what it was like to hear Kento or Fuma or other groups refer to him and Sou and sometimes Shori as “the kids,” how he came close to resenting it every time the term would resurface even after entering his late teen years. And yet…

            At the same time, he could sort of see how years of this – the feeling of responsibility over these younger members foisted upon him – could develop into a solid perspective that would be difficult for anyone to shed.

            Marius’s voice came out gentle as he reassured Fuma. “We’re not going anywhere. We’ll be right here.”

            “You’ll wait for me?” Fuma checked.

            Marius nodded. Waiting for Fuma was something he was all too well-versed with.

 

●●●

 

            “He should be doing his homework on his own, right? I did all of mine by myself, and I have to memorize all the same dance steps. It’s not fair if gets extra help! Right??”

            “Alright, Kento-kun, I’ll go talk to him right now.” Marius placated Kento with swift pats on the back and went off to find the boy offending Kento’s moral sensibilities. Marius might have been more annoyed at Kento if that sweet little face had yet to grow into those large jutting ears, or if he didn’t come away from that interaction with vindication for all the times he was called a brat.

            Marius found Fuma alone, contrary to Kento’s reports, but he was flipping through a magazine instead of buried in schoolwork. “Fuma-kun! You’re setting a bad example for Kento-kun.”

            Fuma pouted but stayed immersed in his magazine. “I thought I was his designated playmate, not his role model. Make your mind up about that.”

            Marius was definitely not going to hear it from either of those two the next time they decided to make fun of him in one of his more petulant moods. “Kento-kun is taking exception to you badgering Sou-chan for his old worksheets. Honestly, I’m not even sure why you’d want Sou-chan’s work, of all people. Shori-kun might have his, still. He’d lend it to you.”

            “If Matsushima-kun is going to treat me like a kid, I might as well act like one.”

            The sentiment hit far too close to home. “Are you bothered by how Sou-chan treats you?” Marius asked.

            “Anyone would be bothered by it!” Fuma asserted. “He acts like he’s on a different level from me because he’s a couple of years older. He’s in junior high just like I am! What’s the deal with putting on airs over such a small gap?”

            It occurred to Marius that this Fuma might harbor different feelings from the “normal” Fuma. It made Marius frown to think of such a possibility, but then it kind of explained why he was on Sou’s case the other day. Fuma seemed to have a bad habit of bullying whoever caught his interest.

            “Maybe it’s not such a small gap to him,” Marius pointed out, loathe as he was to do so. He could hear the hypocrisy in his words. “He’s in high school. Think about it from his perspective.”

            “I have. I’m not stupid.” Fuma paused. “But he can’t think of me that way forever. Someday, we’ll both be in high school. It’s stupid to cling to that image of me as a younger brother.”

            Marius indulged in a quick daydream of recording their conversation and playing it back to the 23-year-old Fuma. And then, he had to return to the responsible older brother shoes he had on loan. “Could you get over that image yourself? Why don’t you try it. Think of someone younger than you. Someone who’s eleven, maybe.”

            Fuma leveled him with a refreshingly non-threatening glare. “Thirteen and fifteen is not the same as thirteen and _eleven_.”

            “Perspectives change too, depending on which one of the two you are.” Marius understood where mini-Fuma was coming from, of course. He understood it all too well. It was definitely odd taking the other side of that argument. “I guess it wasn’t fair to ask that, though. The current you wouldn’t know how you’d feel if you were in Sou-chan’s shoes.”

            “Why are you asking me these questions and answering them yourself?!”

            Fuma was not any less annoyed than he was at the beginning of their talk. As disheartening as that was, Marius had plenty of experience to draw from when it came to providing comfort. True, he was on the receiving end of it more often than not, but that still counted for experience. Conflicting interests on the matter limited him from supporting or denying this younger Fuma’s unspoken feelings, so Marius went for another route. It happened to be one that Fuma frequently opted to take.

            Marius grabbed the much smaller boy by the shoulders, wrapped an arm around them to incapacitate him and began to tickle him mercilessly. He went as far as stealing a line directed at him multiple times before: “I don’t know why I tried reasoning with a brat like you!”

            Fuma squealed at him to stop, protests dissolving into giggles every so often, calling Marius a big, stupid galoot in return.

            As they made their way back to the others, Marius regarded the surprisingly delicate figure of the person he’d grown up admiring. He was sure that that’s what he must have felt like to Fuma all those years ago, whenever Fuma deigned to pull him into a hug or tuck him in his chest when Kento’s soothing words or Sou’s attempts at diversions didn’t do the trick. He was aware of how small he used to be, how fragile he looked, and how he had milked that for all it was worth.

            Marius didn’t want to, but he couldn’t help but empathize with this 15-year-old Sou, and maybe even 23-year-old Fuma. The fact that he had to classify Fuma into two separate identities was proof enough of his own discomfort with the age gap when facing it from the opposite end. Trying to resolve the 13-year-old next to him as being the same person he had a handful of very specific thoughts about was, plainly put, impossible.

            On the other hand, wasn’t 23-year-old Fuma’s reluctance too much? Surely Marius had already given him enough time now. There’d been enough time for Fuma to watch Marius grow up and mature into someone he can take seriously. Otherwise, how much more time could Fuma possibly need?

 

●●●

 

            Upon being reunited with the rest of the group, Marius and Fuma were greeted by the sight of Sou, Shori, and Kento scrambling atop a mess of damp-looking newspapers. The cuff of Sou’s jacket was dirty with some unknown substance. Three heads snapped to attention as soon as the door opened, guilt flashing in their eyes.

            Marius was afraid to ask, but he did anyway. “What did you three do?”

            Sou and Kento turned to Shori, who shrank even more under the attention. “I-I ate too much.”

            “You ate too much,” Marius repeated.

            The cumulative stress of the day caught up to him in that moment, and his heart began to race like a hamster sprinting in its wheel.

            He closed his eyes and longed for what little cool he might have earned from spending enough time in Fuma’s presence.

            Sou cleared his throat. “Um, since you’re here, do you think you could…?”

            Marius opened his eyes and caught Sou gesturing at the mess they made on the floor. “We didn’t know where the mops were,” he explained sheepishly.

            That was when Marius snapped. “You could have asked literally anyone else instead of waiting for me to clean this up!” Sou instantly bowed his head with deference that he normally showed to everyone _but_ Marius. Rather than feel guilty over it, Marius just moved on to Shori. “And you. You’re fourteen! You. Are. Fourteen. What business do you have eating until you throw up? No, don’t cry. I’m the one that wants to cry right now, because you know what? You’re not fourteen. You’re _twenty-one_.”

            Now entirely out of sorts, Marius pointed at Kento. “You’re twenty-four.” He slapped Fuma’s shoulder, ignoring how much slenderer it was than usual. “And you are twenty-three. You never, ever, ever let me forget it!”

            Marius’s head, which had begun to throb from what he thought was pure adrenaline, was assaulted with sudden unbearable pain that made him groan and crouch to the ground like an actual wilting flower.

            Shori’s tears were free-flowing then, and Kento and Fuma clutched either side of Sou’s shirt. The absurdity of the image was one Marius might have laughed at if he weren’t busy dying. Marius flailed his arm to either tell them to go away or come closer – he wasn’t sure – woozily noting how his vision started to go from hazy to dark.

 

●●●

 

            When Marius came to, he found himself in the middle of an empty hallway. He was insulted that his for-now-younger members abandoned him. He pouted and thought that he wasn’t _that_ callous and irresponsible when _he_ was twelve.

            “Marius? What happened to you?”

            _Marius? Not Marius-kun?_

            Marius raised himself up on one elbow and turned to find Sou, _his_ Sou with shorter, lighter-colored hair, the straighter line of teeth, and the same winsome smile. Marius sprung up to his feet to hug him. “You’re you again! You’re taller! Sort of.”

            Sou went from looking confused about the hug to questioning whether he should take offense to Marius’s words. “What’s that supposed to mean?”

            “I think my mom’s friends are witches.”

            Sou blinked at him. “What’s gotten into you?”

            “Not in a derogatory way!” Marius filled Sou in on his theory that his mom’s troop was responsible for transporting him into a world where all their ages were messed up, and that he had to deal with four Benjamin Buttoned members.

            Sou didn’t attempt to assign any of his memories as mere delusions, and that alone helped Marius forget any lingering bitterness over the fact that a younger version of Fuma would’ve latched onto him rather than Marius.

            It was only when Marius’s story caught up to present time that he finally stopped to gauge Sou’s reaction. Sou regarded him seriously, in spite of the many giggles he’d emitted throughout retellings of tattle tales and rehearsal foibles. “The part I don’t get is you complaining to your mom’s friends.”

            “That part?!”

            Sou shrugged. “I thought you like being the youngest.”

            “I do! I don’t want Fuma-kun to be any younger, and I don’t want to lose my position,” Marius ranted, not caring if he was giving himself away.

            “Anything but that,” Sou chuckled. “It had to do with Fuma-kun, then?” Marius didn’t confirm what he already knew. Sou smiled wistfully. “I’m super jealous you got to meet baby FumaKen.”

            “Well, don’t be. I thought they’d be cuter.”

            Sou laughed. “They weren’t? So those old Shounen Club tapes were a lie?”

            “I guess they were cute, until they started talking,” Marius relented slightly. “Or moving around. To be perfectly honest, I think they were worse than us at our age. Although, to be fair, _I_ was _their_ FumaKen, if that makes sense. Who knows how things would have turned out in such a unit.”

            “I like that Kento-kun and Fuma-kun are our parents and not the other way around,” Sou agreed.

            “You have to stop calling them that,” Marius asserted. “You give them fodder to keep treating us the way they do.”

            “But—” Sou started.

            “Fine, I like it, too, for the most part. But I refuse to pine one-sidedly all because you want to perpetuate these literal family roles.”

            Sou had no response to that, at least none that he readily wanted to volunteer. In time, he offered, “Fuma-kun might be using the Half Plus Seven Rule.”

            “The what?”

            “I overheard him talking about it yesterday. You divide your age in half, then add seven years. If you date anyone younger than that number, then it’s considered creepy.”

            “Ehhhh?”

            Sou took out his phone and showed Marius as he made some quick calculations. “Am I doing this right?” he muttered to himself before clearing the numbers and starting again. “There, you’ll have your chance when you’re eighteen and a half. Right now, the oldest person you can date without it coming off creepy is twenty-two.”

            “But Fuma-kun’s just twenty-three!”

            “Eighteen and a half isn’t so far away for you,” Sou said encouragingly. “On the bright side, at least you didn’t fall for Fujigaya-kun.”

 

●●●

 

            “This stopped being cute three years ago. You’re no longer 150cm.”

            Marius stretched out languidly on the couch and only buried his head deeper in Fuma’s lap, letting his fingers curl next to the older man’s thighs.

            Marius considered that he might be straddling the line between asking to be coddled and that unknown territory of something else. He was confused about the right balance of allowing for maturity and staying true to himself, maybe more so than ever before.

            “I’m not trying to be cute,” Marius claimed.

            “Really? If you’re going to let Matsushima be in charge of the cute character all by himself, it doesn’t leave you with a whole lot else.” Whether he was doing it consciously or not, Fuma rested his hand on Marius’s shoulder, idly tapping his fingers to whatever beat was playing in his head.

            “Maybe I’ll take your spot and do all the fanservice with Kento-kun.” Marius beamed up at the shocked expression that flitted over Fuma’s face for half a millisecond. There was also a visible tension in Fuma’s jaw, one that Marius was sure was not caused by the thought of another person doing fanservice with Kento in his stead. Fuma would be one of the first to pimp his symmetry partner out if it were for the good of the group (second only to Kento himself). “I’m sure everyone would be fine with that. You can concentrate on being our best vocalist.”

            “So what you’re saying is, the rest of us should work hard to achieve our goals and you coast by clinging to one of us. You lead a blessed life.” Fuma laughingly gathered Marius’s wrists and held them to the couch. It ended up with the two of them in a pose that closely resembled something out of a movie, hands more or less joined and faces only a breath apart.

            As if on cue, Fuma let go the minute Marius’s head cleared up to formulate the question of _what do I do now?_ And Fuma, of course, patted him on the head like he usually ended up doing after he cottoned on to the fact that they’d landed in a compromising position.

            “You should do it with me,” Marius said. He rushed to do away with the scandalized glaze over Fuma’s eyes. “Fanservice!”

            “That’s no better,” Fuma scoffed. “You have to rely on your own strength. Don’t tell us your only strength is having dubious personal space.”

            “Of course it’s not.” Marius didn’t feel the need to put any power behind his assertion, but he did when he said, “I can wait, you know. Even if it takes longer than six months, or even after my next birthday. I can wait for however long it takes.”

            As Fuma silently parsed his words, Marius remembered the way a thirteen-year-old version of Fuma looked up at him, voicing that very request: _You’ll wait for me?_

            After some time, Fuma granted a response that Marius hadn’t expected. “You don’t have to do that.” Fuma offered a crooked smile, snarky enough to compensate for that uninvited hint of shyness. “But if you’re not just saying that to sound cool, then that’s pretty mature of you.”

            Twenty-three and eighteen was, at the very least, much better than eighteen and thirteen. Marius hadn’t stayed thirteen forever, and neither was he going to stay eighteen forever. Maybe it was youthful naivete, but he had to hold onto optimistic faith in what the future had in store for him.


End file.
